Four cyclists have almost completed an ambitious journey across America to raise vital funds for charity.

The team, based at Royal Naval Air Station Culdrose, are cycling 3,100 miles from one side of the United States to the other in less than three weeks with the intention of raising £20,000 for local and national charities.

The service and emergency service personnel are almost all from the Cornish-based 771 Naval Air Squadron (NAS), the Royal Navy's search and rescue squadron.

The quartet are cycling across the US in 17 days from Oceanside, San Diego in the west to the iconic Times Square, New York City, in the east to arrive tomorrow.

They follow the route of the Race Across America (RAAM) which is an annual endurance event open to solo or team cyclists.

Leading the team is Justin Morgan, a medically-trained Aircrewman who provides the rescue and medical element of the helicopter crew when attending an emergency callout. The two other team members are pilot Ben Carthey and South West Ambulance Service paramedic Wayne Davey. The final member of the team is John Williams, who lives and works on the Isles of Scilly and is the new manager at St Mary's airport fire section.

They are raising money the Royal Marines Charitable Trust Fund and the Children's Hospice South West.

A team spokesman said: "The route itself is not one for the faint of heart. The boys are cycling through a wide range of climates and conditions from the high Rocky Mountain ranges to the scorching heat of the New Mexico desert.

"The planned route sees the team passing through 12 states, 88 counties, 350 communities and climbing 170,000 feet. In the first 1,000 miles, due to the mountainous terrain, the boys climbed the equivalent of Mount Everest four times."